Agro-industrial wastes as corrosion inhibitor for 2024-T3 aluminum alloy in hydrochloric acid medium

Aluminium corrosion in hydrochloric acid media is a huge challenge in the chemical industry; hence, creating green and more efficient inhibitors is an urgent task. Furthermore, the increasing amount of solid waste and its disposal consequences has been a major economic and environmental problem. Therefore, this study aims to determine the protective effect of coconut shell as a potential corrosion inhibitor for AA2024-T3 aluminium alloy in 1 M hydrochloric acid solutions using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques. The results show that the inhibition efficiency increases with an increase in the coconut shell concentration, and the maximum inhibition efficiency reaches 97.91% at 1 g/L. The poten-tiodynamic polarization study shows that the inhibitor acts as a mixed-type corrosion inhibitor. The adsorption of the inhibitor obeyed the Langmuir adsorption isotherm. The surface characterization confirmed the presence of barrier layers covering the aluminum surface. The mechanical properties were also determined and discussed. As compared to the wide range of reported corrosion inhibitors in the literature, the coconut shell has shown to be highly effective for AA2024-T3aluminium alloy. Therefore, it can be suggested that coconut shell waste is a potential corrosion inhibitor for AA2024-T3aluminium alloy in the chemical industry.